Add Conan (C/C++) conan.lock file support (#1230)

Co-authored-by: Christopher Phillips <christopher.phillips@anchore.com>

syft/pkg/cataloger/cpp/parse_conanlock_test.go

@@ -0,0 +1,47 @@
+package cpp
+
+import (
+	"os"
+	"testing"
+
+	"github.com/go-test/deep"
+
+	"github.com/anchore/syft/syft/pkg"
+)
+
+func TestParseConanlock(t *testing.T) {
+	expected := []*pkg.Package{
+		{
+			Name:         "zlib",
+			Version:      "1.2.12",
+			Language:     pkg.CPP,
+			Type:         pkg.ConanPkg,
+			MetadataType: pkg.ConanLockMetadataType,
+			Metadata: pkg.ConanLockMetadata{
+				Ref: "zlib/1.2.12",
+				Options: map[string]string{
+					"fPIC":   "True",
+					"shared": "False",
+				},
+				Path:    "all/conanfile.py",
+				Context: "host",
+			},
+		},
+	}
+
+	fixture, err := os.Open("test-fixtures/conan.lock")
+	if err != nil {
+		t.Fatalf("failed to open fixture: %+v", err)
+	}
+
+	// TODO: no relationships are under test yet
+	actual, _, err := parseConanlock(fixture.Name(), fixture)
+	if err != nil {
+		t.Error(err)
+	}
+
+	differences := deep.Equal(expected, actual)
+	if differences != nil {
+		t.Errorf("returned package list differed from expectation: %+v", differences)
+	}
+}